net: fq_codel: Fix off-by-one error

Currently, we hold a max of sch->limit -1 number of packets instead of
sch->limit packets. Fix this off-by-one error.

Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_fq_codel.c

@@ -195,7 +195,7 @@ static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 		flow->deficit = q->quantum;
 		flow->dropped = 0;
 	}
-	if (++sch->q.qlen < sch->limit)
+	if (++sch->q.qlen <= sch->limit)
 		return NET_XMIT_SUCCESS;
 
 	q->drop_overlimit++;